The focus of this study is on the relationship between lipoprotein metabolism, hypertension, and hyperinsulinemia-insulin resistance in African American males and females. Two populations are available for study - a younger cohort of hypertensives who have been followed for a number of years as part of the Philadelphia Collaborative Perinatal Project and an older group of veterans at the Philadelphia VA Medical Center. In a sub-set of these subjects with either high or low plasma insulin levels after a glucose challenge (insulin sensitive or insulin resistant), we will determine the fractional and absolute synthesis and catabolic rates of apolipoproteins B and A-I, the dominant apoproteins of Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL). We will use stable isotopes and multicompartmental kinetic analysis following an oral bolus dose of deuteroleucine, using gas chromatography- mass spectrometry analytical techniques. Our working hypothesis is that in hypertensive African Americans with hyperinsulinemia, more of the smaller Very Low Density (VLDL) particles are secreted and converted to LDL.